This invention relates to a ring spinning machine comprising spinning stations which are arranged on one side of the machine next to one another in a row and each contain a drafting unit, and comprising depositing sites for cans containing sliver to be spun provided on the other side of the machine and joined directly to the ring spinning machine.
In the case of a ring spinning machine of this type (German Patent Document DE-PS 887 015), the overall width of the ring spinning machine is reduced to approximately half the overall width of the otherwise customary two-sided ring spinning machines so that the ring spinning machines can be set up in groups or pairs in an arbitrary arrangement with respect to one another. The originally one-sided ring spinning machines in this case can be set up in such a manner that at the rear of the ring spinning machine a base is provided which enlarges its standing surface and on which the depositing sites of a row of cans are provided (FIG. 2). It remains open how the slivers are transported from the cans to the spinning stations.
In the case of a two-sided ring spinning machine to which a sliver is fed in cans, partitionless cans having normal dimensions are provided, each of which contain at least four slivers and which are arranged between the rows of drafting units (German Patent Document DE-PS 817 572). In this case, the cans are deposited in an elevated manner on a table arranged above the driving drum or on a conveyor belt arranged above the driving drum in the area of the longitudinal center plane of the ring spinning machine. By way of fixed or rotating guides, the withdrawn slivers are guided to the drafting units in the vertical direction.
On the basis of the German Patent Document DE-PS 11 64 889, a ring spinning machine is known which has an aisle in its interior serving as the operating platform, at both sides of which the drafting units and the rows of spindles are arranged--facing the aisle. In this case, the floor of the aisle is fastened to the machine frame. For each side of the machine, the cans are deposited in four rows underneath the aisle. The slivers are withdrawn in the upward direction and are transported to the drafting units suspended freely along an extremely long path.
On the basis of the British Patent Document GB-PS 10 15 780, a ring spinning machine is known in the case of which the slivers are transported from the cans to the spinning stations by means of transport belts. A second transport belt is assigned to each transport belt so that transport belt pairs are formed which each receive and transport a sliver between one another. The slivers are withdrawn from the cans by way of rollers arranged above them, are transported vertically downward, are conveyed below the floor to the ring spinning machine and are guided from there diagonally upward approximately to the machine center, and farther to the drafting units.
When ring spinning machines spin the slivers fed in cans directly into yarns while eliminating the flyers which are normally connected in front of them, there is the danger that the slivers hang out; that is, are drafted uncontrollably because of their own weight. In practice, ring spinning machines with can feeding have therefore been used only for such slivers which have a relative coarse size and therefore a relatively high strength. However, the spinning of slivers of coarse sizes is very difficult on ring spinning machines since such machines permit only a relatively low delivery speed at the outlet of the drafting units. While the required draft is taken into account, when coarse slivers are fed, the feeding rollers of the drafting units therefore rotate very slowly, that is, at rotational speeds of less than one rotation per minute. Technically, it is extremely difficult to let long drive shafts rotate with sufficient precision at such low rotational speeds, as they are used as feeding rollers of drafting units. There is the risk that these shafts rotate only jerkily so that no controlled draft is obtained.
It is an object of the invention to arrange the depositing sites for the cans in the case of a ring spinning machine of the initially mentioned type in such a manner that the transport paths for the slivers are designed such that finer slivers than previously can be spun into yarns while the space requirements are acceptable.
This object is achieved according to preferred embodiments of the invention in that, for the withdrawing of the slivers, a drivable deflecting guide is provided closely above the cans which is disposed at least approximately in the same horizontal plane as the drivable feeding roller of the pertaining drafting unit.
Even if the cans are deposited in several rows, the transport paths remain so short that damaging free hanging lengths are normally avoidable. As a result, it is possible to also feed relatively thin slivers in cans, that is, slivers of sizes of approximately Nm 0.3 to 0.8. Because of these fine sizes of the slivers, the feeding roller pairs of the drafting units, while the draft is taken into account, can still run at a sufficiently high speed so that a uniformly round rotating is ensured. There is the additional advantage that the three-cylinder drafting units can be used which are customary nowadays in the case of ring spinning machines.
The one-sided ring spinning machine according to the invention may be extremely narrow. The overall height of the drafting units may be arranged in such a manner that, after their withdrawal from the cans and their first deflection, the slivers have to travel along a short horizontal path.
In a further development of the invention, the cans may be deposited on a can platform which is elevated in comparison to the floor of the ring spinning machine. As a result, it is possible to provide the open top side of the cans at a height that results in the shortest path for the slivers to reach the drafting units. Outside diameters of the cans of maximally 300 mm are advantageous as well as a height of the drivable feeding rollers of the drafting units of maximally 1.4 m measured from the floor of the ring spinning machine.
In the case of a further development of the invention, the deflecting guide is a delivery roller. The slivers transported from the deflecting guide to the feeding rollers will then travel through a sufficiently short free hanging length. This development is particularly suitable for slightly coarser slivers.
In another development, the deflecting guide is a deflecting roller around which a drivable transport belt is wound. This development makes it possible, particularly when several rows of cans are present, to bridge a slightly longer transport path without the occurrence of faulty drafts. This development is suitable particularly in the case of very fine slivers.
The transport belts are expediently designed in such a manner that they have a linear course and extend at least approximately to the drivable feeding roller of the drafting unit. In a particularly preferred development, the transport belt winds around the drivable feeding roller and is driven by it. As a result, a separate drive for the transport belts is not necessary.
Expediently, the transport belt is provided with a shield against side air. As a result, it becomes possible to make the transport belts sufficiently narrow without the risk that the transported slivers are blown laterally off the transport belts. Preferably, the shield is constructed as a skid which, in addition to providing protection against side air, also ensures a certain ironing effect which stretches and smoothes the slivers.
In an advantageous development of the invention, the deflecting roller is arranged on an upwardly swivelling frame. As a result, it is possible, also in the case of a low overall height of the ring spinning machine, to carry out manipulations at the rows of cans situated closest to the ring spinning machine without any hinderance of the operating personnel caused by the deflecting rollers assigned to the outside rows of cans. In this case, the deflecting rollers may expediently be a component of a tensioning device tensioning the transport belt.
In a preferred development of the invention, the drivable feeding rollers of the drafting units are arranged as closely as possible to the rear side of the ring spinning machine. This measure contributes to the fact that the free hanging length of the transported slivers can be made particularly short so that faulty drafts are avoided. In this case, it is advantageous for the drafting units to be arranged at a slope of approximately 45 degrees with respect to the horizontal plane.
Preferably, the drivable feeding rollers of the drafting units are constructed as rollers which can be decoupled from a drive shaft. In particular, when the feeding rollers also drive the transport belt transporting the sliver, in the case of a yarn breakage, the feeding rollers and the transport belt can therefore be stopped simultaneously in a simple manner. This has the advantage that, after the elimination of the yarn breakage, the slivers do not have to be newly threaded into the drafting unit. Expediently, in this case, the pressure rollers of the drafting units pertaining to the drivable feeding rollers are constructed as loose rollers of a pressure roller pair. Nowadays, pressure roller pairs represent the customary design in the case of drafting units, and the arrangement as loose rollers makes it possible to stop one pressure roller of the pressure roller pair without interfering with the other pressure roller.
Advantageously, one feeding hopper respectively is connected in front of the drivable feeding rollers for lifting the sliver off the transport belt. As a result, it is ensured that the slivers enter into the feeding roller pairs of the drafting units at the correct point of the pressure roller coatings. It is contemplated that the path along which the sliver is lifted off the transport belt should be as short as possible so that faulty drafts are avoided.
In a case in which the transport of the slivers is not interrupted because of a yarn breakage, it is expedient to assign a sliver deflector to the running transport belt. This will be particularly expedient when a new sliver must be fed after a batch change. It will then be possible to deflect the slivers temporarily from their operational path without having to stop the transport belt and the drafting units.
Advantageously, the depositing sites of the cans are arranged on a conveyor belt. As a result, it becomes possible to automate the supply and the removal of the cans, a can exchange advantageously taking place in blocks.
In an advantageous development of the invention, an air-conditioning duct is assigned to the depositing sites of the cans. The compact placing of the cans with respect to the one-sided ring spinning machine permits an arrangement of an air-conditioning duct that air-conditions the slivers on their transport path to the drafting units. Advantageously, the air-conditioning duct may be arranged in an air-conditioning tunnel which covers the depositing sites of the cans situated between two ring spinning machines. It therefore becomes superfluous to air-condition the whole spinning room.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.